Association between placental location and neonatal outcomes in manual fundal pressure-assisted vaginal deliveries: A retrospective single-center study in Japan

Aim Manual fundal pressure (MFP) is still used to assist vaginal deliveries during the second stage of labor in predominantly lower-middle income countries; however, there is insufficient evidence on the risk factors in MFP-assisted vaginal deliveries for adverse neonatal outcomes. The aim of the present study was to investigate the association between placental location and neonatal outcomes in MFP-assisted vaginal deliveries. Methods The present study was a single-center retrospective cohort study in patients with all MFP-assisted vaginal singleton deliveries from January 2016 to December 2020. Placental location was divided into two categories: posterior-lateral and anterior-fundal. The primary outcome was a neonatal adverse composite including umbilical artery blood pH <7.2, Apgar score <7 at 5 min, neonatal intensive care unit admission and neonatal resuscitation. We used multivariable logistic regression models to investigate the association between placental location and neonatal outcomes. Results We extracted 522 MFP-assisted deliveries among 5053 vaginal deliveries. The proportion of posterior-lateral and anterior-fundal placentation was 239 (45.8%) and 283 (54.2%), respectively. The crude prevalence of neonatal composite outcome in the anterior-fundal group was significantly higher than that in the posterior-lateral group (39.6% vs. 28.9%; p = 0.013). Multivariable logistic regression analysis found that the prevalence of neonatal adverse outcome in the anterior-fundal group was significantly higher compared with the posterior-lateral group (adjusted odds ratio, 1.52; 95% confidence interval, 1.04-2.23). Conclusion Anterior-fundal placentation was significantly associated with an increased risk of neonatal adverse outcomes compared to posterior-lateral placentation in MFP-assisted vaginal deliveries.